Bash If Return Code Not Zero

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I like to include the name of the program in the error message to make clear where the error is coming from. If the exit code of ./tmp.sh is 1 however, the commands within the parenthesis will be executed next. The second use, ${1:-"Unknown Error"} means that if parameter 1 ($1) is undefined, substitute the string "Unknown Error" in its place. An AND list has the form command1 && command2 command2 is executed if, and only if, command1 returns an exit status of zero. navigate here

current community chat Stack Overflow Meta Stack Overflow your communities Sign up or log in to customize your list. Linux is a registered trademark of Linus Torvalds. Here is an illustration showing that if conditions may also be nested. To explain how they work, I will quote from the bash man page: "The control operators && and || denote AND lists and OR lists, respectively. her latest blog

Bash Set Exit Code

if [ $RESULT -eq 0 ]; then echo success else echo failed fi if [ $RESULT == 0 ]; then echo success 2 else echo failed 2 fi share|improve this answer How can I slow down rsync? What is the importance of Bézout's identity? More exit codes The exit command in bash accepts integers from 0 - 255, in most cases 0 and 1 will suffice however there are other reserved exit codes that can

You don’t want to mount onto ${MKAPP_BUILDDIR}/tmp unless it exists, so (IMNSHO) the correct fix to the script is to leave the || return 1 alone, and delete the if [ Exit Code 0 is always the same as $pipestatus[-1]. The sample script runs two commands touch and echo, since we did not specify an exit code the script exits with the exit code of the last run command. ls | bogus_command # bash: bogus_command: command not found echo $? # 0 # Note that the !

up vote 74 down vote favorite 26 Is there any way to check if there is an error in executing a command? to negate the test as well, to prevent us having to use else as well: # Best if ! The exit status of a command From Linux Shell Scripting Tutorial - A Beginner's handbook Jump to: navigation, search ← Multilevel if-then-elseHomeConditional execution → Each Linux command returns a status when http://icicit.org/exit-code/bash-return-code-if-then.html Any link to docs please? –Swaroop C H Sep 18 '08 at 6:15 1 @SwaroopCH set -e your script will abort if any command in your script exit with error

Browse other questions tagged bash shell or ask your own question. Bash Exit On Error But if you want to test whether a command succeeded or not, use the command itself directly with if, as shown above. Testing for exit codes Earlier we used the $?

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Within the parenthesis the commands are chained together using the && and || constructs again. You're running ping in a subshell of a subshell, the output of ping is captured in view of running it as a command. asked 2 years ago viewed 282 times active 2 years ago Related 10Bash script to detect the version control system by testing command return status1Redirect hard return to other terminal1Using sshpass, Exit Code 1 Why does Harry address the Weasley-parents with "Mr. & Mrs"?

COMMAND_LAST # Will exit with status of last command. Why is my scene rendered repeatedly when I press F12? IBM documentation says otherwise. –Patrick James McDougle Aug 12 '14 at 20:56 add a comment| up vote 13 down vote [ $? -eq 0 ] || exit $?; # exit for weblink To add our own exit code to this script, we can simply use the exit command.

echo $? # Non-zero exit status returned -- command failed to execute. only gives you the return code of the last element in the pipe so, in the code: ls -al file.ext | sed 's/^/xx: /" will not return an error code if